<head>
  <meta charset="utf-8">
  <meta http-equiv="Content-Language" content="zh-cmn-Hans" />
  <meta http-equiv="x-ua-compatible" content="ie=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <!-- Global site tag (gtag.js) - Google Analytics -->
  <script async src="https://www.googletagmanager.com/gtag/js?id=G-28P0PYCRZ9"></script>
  <script>
    window.dataLayer = window.dataLayer || [];
    function gtag(){dataLayer.push(arguments);}
    gtag('js', new Date());
    gtag('config', 'G-28P0PYCRZ9');
  </script>
  
  <script>
    var _hmt = _hmt || [];
    (function() {
      var hm = document.createElement("script");
      hm.src = "https://hm.baidu.com/hm.js?fa71f2474b82505e00203cf9956cf0bc";
      var s = document.getElementsByTagName("script")[0]; 
      s.parentNode.insertBefore(hm, s);
    })();
</script>

  {% assign desc = page.description | default: page.excerpt | default: site.description | strip_html | strip_newlines | truncate: 160 -%}
  <meta name="description" content="{{desc}}">
  <title>{% if page.short-title %}{{page.short-title}}{% else %}{{page.title}}{% endif %} | {{site.title}}</title>

  <!-- Favicon / Touch Icons -->
  <link rel="icon" sizes="64x64" href="/assets/shared/dart/icon/64.png">
  <link href="{% asset touch-icon-iphone.png @path %}" rel="apple-touch-icon">
  <link href="{% asset touch-icon-ipad.png @path %}" rel="apple-touch-icon" sizes="152x152">
  <link href="{% asset touch-icon-iphone-retina.png @path %}" rel="apple-touch-icon" sizes="180x180">
  <link href="{% asset touch-icon-ipad-retina.png @path %}" rel="apple-touch-icon" sizes="167x167">

  <!-- Twitter Card -->
  <meta name="twitter:card" content="summary" />
  <meta name="twitter:site" content="@dart_lang" />
  <meta name="twitter:title" content="{{page.title}}" />
  <meta name="twitter:description" content="{{desc}}" />

  <!-- Open Graph -->
  <meta property="og:title" content="{{page.title}}" />
  <meta property="og:description" content="{{desc}}" />
  <meta property="og:url" content="{{ page.url | absolute_url }}" />
  {% assign og_image_path = page.og_image | default: layout.og_image | default: '/assets/shared/dart-logo-for-shares.png' -%}
  {% assign og_type = page.og_type | default: layout.og_type -%}
  {% comment %} Add page URL to page relative paths {% endcomment -%}
  {% assign og_image_start = og_image_path | slice: 0 -%}
  {% unless og_image_start == '/' %}{% capture og_image_path %}{{page.url}}/{{og_image_path}}{% endcapture %}{% endunless -%}
  <meta property="og:image" content="{{og_image_path | absolute_url}}{{site.og_image_vers}}" />
  {% if og_type -%}
  <meta property="og:type" content="{{og_type}}" />
  {% endif -%}

  <link href="https://fonts.googleapis.com/css?family=Google+Sans:300,400,500|Google+Sans+Display:400|Roboto:300,400,500,700|Roboto+Mono:300,400,700|Material+Icons" rel="stylesheet">
  {% asset main.css %}
  {% for css in page.css -%}
    <link href="{{css}}" rel="stylesheet" type="text/css">
  {% endfor -%}
  {% asset main.js %}
  {% for js in page.js -%}
    <script {% if js.defer %}defer{% endif %} src="{{js.url | default: js}}"></script>
  {% endfor -%}
  {% include analytics.html %}
 </head>
